Triangulation Options

The Triangulation options panel controls how Regina works with 3-manifold triangulations.

The settings here are:

Default top-level tab

Specifies which tab in the triangulation viewer will first appear when you open a triangulation for viewing.

Default skeleton tab

Specifies which sub-tab will first appear when you switch to the triangulation skeleton tab.

Default algebra tab

Specifies which sub-tab will first appear when you switch to the triangulation algebra tab.

Surface calculation threshold

Determines when Regina will automatically compute information on the triangulation recognition tab that requires the enumeration of normal surfaces (such as 0-efficiency testing, 3-sphere recognition, or unknot recognition). If the number of tetrahedra is at most the given value, then Regina will compute such information automatically. If the number of tetrahedra is larger, then Regina will not compute this information until you manually press the Calculate button.

Note that some algorithms (such as 3-sphere, 3-ball and solid torus recognition) might use a lower threshold than the one you set here. This is because they rely on even more complex operations, such as enumerating almost normal surfaces, which in the worst cases are much slower than ordinary normal surface enumeration.

Labels on face pairing graphs

If checked, Regina will label each node in the face pairing graph with the corresponding tetrahedron number.